<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../react资料_stu//依赖包/react.development.js"></script>
    <script src="../react资料_stu//依赖包/react-dom.development.js"></script>
    <script src="../react资料_stu//依赖包/babel.min.js"></script>
</head>

<body>
    <div id="app"></div>
    <script type="text/babel">
        class App extends React.Component{
            constructor(){
                super();
                // 构造器中的this指向组件实例
                this.handle=this.handle.bind(this)
            }
            state={
                count:0
            }
            render(){
                const {count}=this.state;
              
       return(
        <div>
            <button onClick={this.handle}>+</button>
            <p>{count}</p>
            </div>
       )
            }

            // 事件函数
        handle(){
            alert(1)
            //在组件中,我们希望事件函数的this指向组件实例,这样可以拿到state等各种数据
            console.log(this);
        }
        
        }
        

        ReactDOM.createRoot(document.getElementById('app')).render(<App/>)

    </script>
</body>

</html>